Iron deficiency is the most common micronutrient deficiency in the world today, affecting more than 4 billion people globally. It is estimated that 2 billion people—over 30% of the world's population—are anaemic (WHO, http://www.who.int/nut/ida.htm, accessed 20 Dec. 2005). Iron deficiency is not a problem solely confined to the developing world. Epidemiological surveys performed in European countries show that iron deficiency concerns 10-30% of menstruating women and iron deficiency anaemia (IDA) 1.5 to 14% (Hercberg et al., 2001; Goddard et al., 2005). Iron deficiency anaemia can result in decreased intellectual performance, decreased physical capacity, alterations in temperature regulation, alterations in the development of gestation, and compromised immune and metabolic functions, all of which impact upon quality of life and health economics (Edgerton et al, 1979; Hercberg et al, 2001; Scholz et al, 1997). The standard first line treatment for simple mild IDA is, commonly, supplementation with oral ferrous sulphate. More complex or severe iron deficiencies may be treated with intravenous iron or blood transfusions, but subsequent management is with oral iron preparations. In spite of the widespread use of oral iron preparations their effectiveness is poor. This is due to: (i) variable absorption characteristics and (ii) side effects resulting in poor compliance. Strategies for the prevention of iron deficiency include the use of iron-fortified foods. Commonly used fortificants include ferrous sulphate, ferric chloride, ferric sodium EDTA and ferric pyrophosphates. However, despite fortification strategies, iron deficiency remains a common global problem and, thus, cheap and effective supplements are required.
WO 2005/000210 describes the synthesis of high molecular weight iron saccharidic complexes formed when freshly precipitated iron hydroxides are subsequently aggregated with sugar molecules to form secondary complexes. These complexes are acknowledged to be agglomerated mixtures.
WO 03/031635 relates to an enzymatic method to prepare calcium gluconate where the crystals are high purity and high solubility.
US 2005/0209322 describes a process for making sodium ferric gluconate complexes for i.v. iron administration that requires the initial step of preparing ferric hydroxide with a subsequent step of reacting with the ligand, sodium gluconate. US 2005/0209187 relates to a similar process for making iron sucrose complexes rather than iron gluconate complexes.
US 2003/0049284 describes a method for increasing the solubility of salts of alpha hydroxy carboxylic acids, by reaction with an alpha amino acid, such that the material would have improved nutritional supplementation properties.
U.S. Pat. No. 3,679,377 relates to the provision of an agronomically effective source of iron in a plant nutrient solution as a soluble ferric sulfato-hydroxyl complex anion. The materials produced are conventional ligand-metal ion complexes.
DE 20 2005 014332 U1 discloses metal-organic nanopowders for use in materials engineering such as the formation of polymeric composites through injection spraying or coating of the nanopowders into or onto an existing material.
Jugdaohsingh et al. (2004) describes a critical precipitation assay that utilises a solution phase reaction in which, at peri-neutral pH, organic acids compete with the formation of the oxo-bridges between aluminium atoms in the polymerisation process, limiting the growth and decreasing the branching of the polyhydroxy aluminium species (Jugdaohsingh et al. (2004); Powell et al. (2004)). The assay is usable because the efficiency of the ligand in interrupting this process is related to its affinity for aluminium. It was also noted in this work that during solution-phase growth of polyhydroxy aluminium species, the ‘competing ligand’ becomes incorporated within the polymer.